At least she admitted that much wrongdoing, and that calmed him somewhat. A little bit. At least until she brought his dad into the conversation, and James hadn't always agreed with his dad but he had loved the man, and she made assumptions.
"My father said a lot of things, but he never called you anything but a Muggleborn, and that's what you are."
A truth. One even she couldn't refute.
This was a difficult conversation, and James took a deep breath, angry at her, at his father, and yeah, a little angry at the moment at Harry for inconveniently existing and being the reason for the argument. Mostly at his dad, though, for being his dad and someone he had to love no matter what, and for also having said and done the things he had. His father had been one of the most contradictory people James ever knew, loving and gentle while couching him against marrying the woman he loved.
"My father wanted what was best for me, and you probably won't believe it but he wanted what was best for you, too, even if the two of you never met."
James took another breath, some of the anger bleeding away as he considered her fears, all of which were legitimate, he realized. He didn't want think think his father would have wanted her to abort the baby, but if he'd thought it the best thing for both of them at the time? Yeah, he might've. Might even have wanted her to give the baby up, try to pass it off as an orphaned cousin.
"I wouldn't have let that happen," he said, quiet but firm. "If I had known, I would have married you. Right then. He couldn't have stopped me."
And from the stubborn set of his chin and eyes, he at least believed it.